Container closure manufacture



June 15, 1948. G, c, ERB 2,443,185

CONTAINER CLOSURE MANUFACTURE 5 Sheets-Sheet 1 Filed April 12, 1946Arrow/5Y8 -June15,1948. G, c. ERB 2,443,185

CONTAINER CLOSURE MANUFACTURE Filed April 12, 1946 5 Sheets-Sheet 2 ,z mBYj 09 KMOJ/EWL June 15 1948' Filed April 12, 1946 CONTAINER CLOSUREMANUFACTURE 5. Sheet ..s 3

June 15, 1948.

G. c. ERB

CONTAINER CLOSURE MANUFACTURE Filed April 12, 1946 V 5 Sheets-Sheet 4 J.(i 22 mm KMi/M Arron/vars Jun 15, 1948. G. c. ERB 2,443,185

CONTAINER CLOSURE MANUFACTURE Patented June 15, 1948 UNITED STATE-SOFFICE George C. Erb, Forest Hills, N. Y., assig nor to American CanCompany, New York, N. Y., a corporation of New J b'rsey ApplicationApril 12, 1946,-Serial N0.-6fi1,'1.54

7 Claims. (Cl. 113-121) This invention relates to the method ofpreparing metallic closures for containers and has particular referenceto the manufacture of easy removable sealing caps formed with anintegral concentric hollow pull ring surrounding the cap.

An object of the invention is the provision of a method of preparingmetallic closures for containers holding carbonated gaseous liquids suchas beer and the like, wherein a smooth hollow ring is formed integralwith and surrounding a sealing cap which cap may be applied readily tohermetically seal-such a filled container for preserving its contents,the cap being removable without the use of tools by merely lifting andwithdrawing the ring to effect opening of the container.

Another object of the invention is the provi sion of a method of makingmetallic crown cap closures for containers wherein a'central portion ofa blank is formed to provide a cap or closure element and wherein anintermediate annular section is cut to provide a space and an integralconnection between the closure element and an outer surrounding portionto substantially separate the central and outer surrounding portions sothat the latter may be formed into a hollow pull ring for use inremoving such caps from sealed containers.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following description, which, takenin connection with the accompanying drawings, discloses a preferredembodiment thereof.

Referring to the drawings:

Figure 1 is a top plan view of a crown cap closure having an integralhollow pull ring adapted for manufacture according to the steps of thepresent invention;

Fig. 2 is a side elevation of the cap closure and pull ring shown inFig. 1;

Fig. 3 is a sectional view of the closure illustrated in Figs. 1 and 2in a sealed position on the mouth of a container;

Fig. 4 is a side elevation showing the pull ring in a raised position asan incident to removing the closure from a sealed container;

Fig. 5 is a plan view on a reduced scale of a blank disc having a drawncentral portion which results from the first step of the method ofmakingthe crown cap closure;

Figs. 6, 7, 8, 9 and 10 are similar views showing further steps in themanufacture of the closure;

Figs. 11, 12, 13, 14 and 15 are sectional views of the diepa'rts ofapparatus suitable for forming l 2 the cap closure in a series of stepsaccording to the present inyentionjlig. 11 showing the step of formingthe drawn disc of Fig. 5 and the mechanism being shown in Figs. 12, 13,14 and 15 producing various steps in the cap closure manu- 'facture asrespectivelyshown in Figs. 6 to 9, inclusive;

16 isacross sectionalview taken along the section line l6l6 in Fig. .15;and

Fig. 1!? is-a sectional view of the die parts of apparatus'usedin thefinal manufacturing step which produces the finished cap of ill. 4

:As a preferredembodiment-ot theIinvention the drawings .illustratefthemanufacture of an easy removable closure orcrown type sealing capA andshow the several method'steps constituting the presentinventionrwhlchare used to produce such a closure.

The closure includes alhollow pullring B (Figs. 1 and 2) formed integralwith the cap A. Such a ring preferably is connected to the cap by acurved bridge :6. The cap A is sha'pedto provide for a gasket D whichforms a sealing area between the cap A and the part of a container E-adapted torecelve the cap; Such aca'p'is crimped in place according tothe well known crownsealing type of closure;

Thissealing capis preferably formed from suitable metalf-stook-Ff'iFig.11) and is first blanked out as a circular disc G (Fig. 5) In the same0pelalfion-the' cap disc may be drawn or cupped preparatory toproviding-for the reception of the gasket D. These two operations areperformed in a'sui'tabledie mechanism such as is disclosed in 11. Aconsideration of this mechanism now will be had.

A stationary die 13 is mounted upon a die support M of conventionalpressconstruction. The stock' F is positioned over the die l3 preparatory tothe blanking an'd drawing operation. The die I3 is removably held inplace by clamp bars l5 which are bolted to the die support by cap screws16.

The die l8 provides the female part for the blanking operation andaccordingly is formed with a substantially vertical'cutting wall I! atthe center. A draw block 18 is located for slight vertical movementwithin the opening formed by the 'wall I 1- oftli'e' die l3 andlssupported in the usual manner upon pins connected with the standardrubber'or' spring cushion which provides a-yi'eldlng die element. Thedraw block I8 is apertured to'p'rovide' a clearance opening 2| and apanel'center block '22 projects up through the aperture; Panel block-his. secured to the die support H by screws 73.

A punch 34 constitutes the male blanking element and is disposed inaxial alignment with the die mechanism, the outer diameter of the lowerpart of the punch cooperating with the cutting wall l l of the die I 3to blank out the disc G when the punch parts are lowered in the blankingoperation. The punch 34 is carried by a crosshead 35 and is secured tothe head by cap screws 36. A knockout pad 31 has sliding movement withina central opening 38 formed in the punch 34 and is carried on the lowerend of a vertically disposed knockout rod 39 which extends. upthroughthe crosshead 35.

A spring 4! surrounds the 'lower" end of the knockout rod and isdisposed within a cylindrical opening 42 which merges with the opening38 of the punch 34. This spring at the lower end rests upon the knockoutpad 3'! and is confined at the upper end by a wall f ;;the cylindricalopening.

Prior to the blanking operation, the upper face of the draw block I8 isflush with the upper surface of the die l3. This plane also'includes thetop of the panel center block 22. The draw block I8 is held in raisedposition at such a time, At the time the stock F is inserted intothe'die mechanism, the crosshead 35-and' the parts carried thereby arein raised position. The spring 4l holds the knockout pad 31 aslight'distancc below the surface of the punch 34.

When the punch parts descend for this operation the knockout pad 37first engages the stock F and clamping it against the panel block 22,holds the work in position on the die, The disc G is severed from thestock as the descending punch 34 forces down that part of the stockwhich is engaged between the punch and the draw block l8. At the sametime the center part of the disc, which is prevented from moving down bythe panel center block 22, is drawn at its surrounding edges to providea central cup section 45 (see also Fig. for the disc G.

After the disc has been cut and the center portion has been drawn, thepunch is raised whereupon the blanked out disc G is lifted by the risingdraw block I8 and the knockout pad 31 operates to eject the disc fromthe punch mechanism.

In the second operation a slit disc H is produced as shown in Fig. 6.Portions-0f the disc G are pierced or slit to provide this stage in themanufacture of the sealing cap A and this operation may be performed inthe mechanism illustrated in Fig. 12. This mechanism comprises astationary die 52 which is held in the usual manner on a die support 53by clamp bars 54 secured in place by cap screws 55. The disc G is placedupon the die 52 in an inverted position, i. e., the central panel 45extends downwardly into a recess 56 formed centrally of the die 52.

The die 52 is formed with a crescent shaped slit 5'! which extends fromthe top of the die to the top wall of a bottom recess 58. A crescentshaped draw ring 6| extends upwardly through the opening 51 in the die52 and is an integral part of a circular draw block 62 which is movablylocated within the recess 58 of the die 52. The draw block 62 issupported in the usual manner upon pins connected with the standardrub-. her or spring cushion which provides a yielding die element. Whenthe work is inserted for this operation the upper face of the draw ring6| is fiush with the upper surface of the die 52.

The corresponding punch parts for the die members 52, 6| include aknockout disc 64 which is carried on the lower end of a-knockout pad 65which preferably is a part of a vertically exknockout pad 65 is looselycontained therein. The lower surface of the knockout disc 64 is slightlybelow the lower surface of the punch piercing die II. It is held in thisnormal position by a spring 15 which surrounds the rod 66 and isconfined within a recess 16 formed in the crosshe'ad 61. The lower endof the spring rests upon the knockout pad 65 and its upper end isconfined within the upper wall of the recess 16.

When the punch mechanism is lowered to perform the piercing operation onthe disc G the knockout'member 64 first engages the discand holds it onthe die with its drawncenter panel 45 resting within the recess 56 andthus centering the work." The piercing punch H cooperating with thecrescent shaped slit 5! in the die 52 cuts through the disc-and forcesthe engaged stock with -the.draw ring. 6| which recedes as the cushionsupport for the draw block 62 is overcome. 1

The piercing operation removes and slightly lowers a crescent shapedscrap piece .I'! from the disc G leaving acrescent shaped opening 18 andthus forming slit disc HcfFig. 6. Upon thereturn of the punch mechanismthe piercing punch ll iswithdrawn from the disc H;Whi1e it is held bythe knockout disc 64. The scrap 11 moves back into the-opening 18 of thedisc and when the punch element has been fully; raised the disc isreleased and may beremoved in any suitable The next operation has to dowith further drawing a portion ofthe slitdisc H so that the central partassumes the general shape of the crown cap. This produces a cap formeddisc J (Fig. :7). This stage in theoperation according to the presentmethod steps may be performed by mechanism illustrated in Fig. -13,an-dreference now will be had to the cap forming oper- The cap formingmechanism of Fig. 13 comprises a central forming die 8i which is mountedupon a. diesupport 82 and is held in stationary position by cap screws83. A circular draw ring 84 is located above thedie support 82 andsurrounds the die 8|. The .draw ring 84 has slight vertical movementrelative to the die and is supported in the usual manner upon pinsconnected with the standard rubber or spring cushion which provides ayielding element. A holding ring 85 surrounds the draw ring 84 andlimits its vertical movement. When the slit disc H is first placed uponthe die 8| preparatory to the cap forming operation, the disc .isstillin an inverted position, the same as in the mechanism of Fig, 12.The draw ring is in a raised position, its upper surface being .flushwith the upper surface of the die. 4

The support ring 85 is bolted by cap screws 86 to the die support 82. Atthe top the. die. BI is formed with a centrallyfiisposed recess 81 andthe drawn center 45 of the slit disc H is adapted to fit snugly withinthis recess. This centers the slit disc on the die preparatory to thecap forming operation. The die 8! adjacent its upper sur-.

.5 lace is also formed with a conical wall 88. This constitutes the maleelement for the cap forming operation. 7

The associated punch mechanism for the die 8| comprises a punch 9| whichis formed integrally with or is carried on a suitable crosshead body 92;Punch BI is formed with a central opening 9-3 which has diiferentdiameters. At the bottom of the punch the opening is outlined by asurrounding conical wall 94 which is coaxial with and parallel to theconical die wall 88.

A knockout pad 95 has restricted movement in the lower end of theopening 93 of the punch 91 and the hottom'part of the padnormallyextends down into the space adjacent the wall 94. It is held inits normal position by a spring 96 which surrounds a knockout rod 91located in the opening 93. The lower end of the rod is connected withand carries the knockout pad. Spring '96 rests upon the top of theknockout pad and its upper end is confined against the up per wall ofthe adjacent part of the recess in the punch. At the bottom the knockoutpad 95 is formed with a circular projection '98 which snugly fits withinthe drawn center 45 of the slit disc H when the punch parts descend.This centers and properly locates the disc in the die for the capforming operation.

When the punch mechanism is lowered upon the slit disc H the projection$8 of the knockout pad 95 first engages within the drawn center 65 ofthe slit disc and seats that part of the disc fully within the recess 31of the die. About the same time the punch BI clamps the outer part ofthe slit disc against the upper face of the draw ring 84 As the punchdescends further the spring 96 yields as 'does also the spring cushionsupporting the draw ring 84 whereupon that part of the disc surroundingthe center 45 and inside of the crescent slit 18 is wiped down over thedie BI. In this action the conical wall 88 of the die cooperates withthe conical wall 94 of the punch and draws a cap section IIII (Fig. 7)having a short skirt 1'02 for the adjacent area surrounding the crescentshaped slit I8. The section of the cap between the ends of the slit I8is drawn down even farther into a longer skirt I03 to provide the bridgeC for the crown cap. Fig. 13 shows the fully formed disc J as it restswithin the die, this being at the time the punch mechanism is on itslowermost stroke.

When the punch 9! moves up the spring 96 still holds the knockout pad 95against the newly formed disc J whereupon the cushion operating againstthe draw ring 84 lifts the ring and also the formed disc so that it isbrought up above the upper surface of the die BI. At the same time thelower face of the punch 9I moves up to a position above the uppersurface of the newly formed disc and these combined actions strip thedisc from the die mechanism.

After the cap formed disc J is completed it is usually desirable to trimthe outer edge of the disc .prior to further forming operations on thecap. This insures a better formed, more uniformly dimensioned easy opencrown cap closure. A trimming die of simple construction is illustratedin Fig, :14 and may be used for this purpose.

The trimming die unit comprises a die I which is mounted upon a diesupport I06 and is held in place by clamp =bars I01 and cap screws 4-08.Thedie 10.5 is apertured and a cutting wall 411 is formed in the centerand adjacent the upthe upper surface of the draw block H2 is flush Iwith the upper surface of the die I05.

The corresponding punch mechanism comprises a punch member H3 which maybe a part of a suitable crosshead H4 disposed for vertical movement andalignment relative to the die.

The punch II 3 is apertured at H5 and a knockout pad H6 is located inthe aperture of the punch. This knockout pad is mounted on the lower endof a knockout rod II'I. Normally the knockout pad is disposed in itsuppermost position within the recess I I5. It is held by a spring 4 I8which surrounds theupper portion of the rod IIT and is located Within arecess I I9 formed in the upper part of the crcsshead H4.

The spring I I8 is seated upon the lower wall of the recess H9 and itsupper end engages a collar I 2| which is pinned to the upper end of therod. Recess H5 of the punch H3 is surrounded at the bottom of the recessby a conical wall I22. This wall is of a dimension and angle to snuglyfit over the section IBI of the formed cap disc "J.

The cap formed disc J is placed upon the die mechanism for trimming inan upright position. It is located within a locatin ring I23 which ismounted upon the die I and which extends partially around the die. Withthe disc J in place and supported both by the die I 05 and the drawblock H2, the punch mechanism descends. The conical wall I22 of thepunch moves down around the formed skirt portions I82, I03 of the disc Jand further holds the disc in position for the trimming operation. Thetrimming operation is performed by the punch I I3 forcing the disc andthe draw block H2 downwardly into the position shown in Fig. 14. Thiscuts through the disc and leaves a surrounding trim I25 which is held inplace within the locating ring I23.

As the punch mechanism. is withdrawn the newly trimmed disc (designatedby the letter K) moves under action oi the ascending draw block H2 untilit is crought back into the plane of the trim l 25. Further upwardmovement of the punch lifts the trimmed disc K which is frictionallyheld in the conical wall l 22 of the punch until it is free of the die.A suitable striking force is then applied to the upper end of theknockout rod H 1 this lacing a conventional knockout action which causesthe knockout pad IE6 to descend sufiiciently to strip the trimmed discfrom the punch mechanism. The scrap trim I25 drops away from the die inthe usual manner.

The nest step in. the formation of the crown cap has to do withinitially and partially forming the ring B which" it will be recalled isan integral part of the closure, the material for the ring 'b-Billg thestock surrounding the slit 18. This stage in the operation is performedby a punch and die mechanism illustrated in Fig. 15 and the resultingring formed disc, designated by the letter M. is shown in Fig. 9. Duringthis partial forming of the ring the center cap area. is'not altered inany manner and the trimmed disc K which is to be formed into the ringformed disc M is placed in the die mechanism in an inverted position,that is, with the cap section IUI and skirt extensions I02, I03 at thebottom.

The punch and die mechanism of Fig. com prises a stationary die I3Iwhich is secured by a cap screw I32 to a die supportv I33. The die I3Iis formed with a central recess I35 which is nonconcentric with the axisof the die. In the central recess there is disposed a draw block I36having a locating depression I31 formed in its upper surface.

The draw block I36 has vertical movement within the recess I35 and issupported in the usual manner upon pins connected with the standardrubber or sprin cushion which provides a yielding die element. A centralcap screw I36 prevents displacement of the draw block I 36 whileallowing for the required vertical movement, this cap screw havingthreaded connectlonin the die'I3I.

A draw ring I4I surrounds the die I3I and is held in position by aclamping ring I42 secured by cap screws I43 to the die support I33. Drawring HI has vertical movement withinthe clamping ring I42 and-relativeto the ,die I3I. Draw ring I is'supported in the usual manner on pinsconnected'with the standard rubber or spring cushion which provides a.second yielding die element for this die mechanism. a r

The normal position of the vertically movable members I36, MI is withtheir upper surfaces flush with theupper surface of the die I3I, Thelocating depression I31 formed in the draw block I36 provides acenteringpocket for receiving the drawn cap section I IlI "of thetrimmed disc K in the die thus locatin'gthe disc preparatory to the ringforming operation.

The corresponding punch mechanism includes an outer punch member I5Iwhich is secured by cap screws I52 to a vertically movable crossheadI53. The punch member I5I is recessed as at I54 to provide .for certainfixed and movablepunch parts, i. e. fixed and, movable relative to thepunch. The inner wallof'thisrecess is circular. A central punch memberI55 constitutes one of the fixed parts'and is secured by cap screws I55(see also Fig. 16) to the punch I5I.-- Theinner member I55 has anexterior circular wall which is concentric with and is spaced inside ofthe inner wall of the recess I54. This exterior circular wall isinterrupted on one side by a straight wall I51 for a purpose hereinafterexplained.

The movableparts contained within the recess I54 include a tubularclamping ring I6I which fits within the space between the central punchmember I55 and the inner wall of the recess I54. The central punch I55is slotted along parallel lines extending across the center as at I62and this provides clearance for a connecting bar I63 which extendsacross the diameter of the punch and which carries the tubular clampingmember I6I. By reason of this construction the tubular clamping membermay be raised and lowered within the recess I54 of the die I5I.

The bar I63 is carried upon the lower end of a vertically disposed rodI65 which extends up through the crosshead I53. Adjacent the bottom endthe rod I65 is formed with a collar I66 which is movable within atubular recess I61 formed in the crosshead. The normal position of themovable parts of-the punch including the clamping member I6I is with thelower face of the clamping member flush with the lower face of the punchISI. This is also flush with the lower face of the relatively fixedinner punch member I55.

A spring "I surrounds the rod I65 and is located within the recess I61of the crosshead I53. This spring normally holds the clamping and withits cap center located within the recess I31 of the draw block I36 thepunch mechanism descends and the punch I5I first clamps against theouter flange of the trimmed disc and presses it against the draw ringI4I. Inside of this area of the fiange the clamping ring I6I engages thetrimmed disc and presses it down on the forming die I3I. That partof-the punch member I55 which surrounds the pocket I68 engages thatportion of the trimmed disc K which is inside of the central areaengaged by the clamping ring and presses it against the draw block I36.I

As the descending punch continues its downward movement the clampingblock I Hi holds the engaged disc on the stationary die I3I while theparts I5I and I55 move down. The punch I5I bends over the outer edge ofthe disc in an annular flange I15 (Fig. 9) which extends around theentire disc. At the same time the central punch member I55 wipes down onthe inner edge adjacent the slit 18 of the disc and forms an innercircular flange I16 which extends around the disc between the ends ofthe bridge portion C.

The result of this dual bending on the disc edges is the formation of aU-shaped section I11 which extends around the periphery of the discexcepting the region of the bridge section C. It is this U-section I11which provides the stock for the pull ring B, the final shaping of thering as well as a scalloping of the skirt part I02 of the cap takingplace in the next and final die operation.

Fig. 10 illustrates the results of the final cap end ring formingoperation which creates the easy open closure sealing cap A of Figs. 1and 2 It is to the die mechanism used in this operation that attentionis now directed.

Fig. 17 illustrates a mechanism suitable for completing the formation ofthe ring and for scalloping the edge of the crown cap. Such a mechanismcomprises a center die block I8I which is carried on a die support I62being held in stationary position by a cap screw I83. A draw ring I84surrounds the die ISI and has slight vertical movement. This draw ringis retained in position by a clamping ring I85 which is secured by capscrews I86 to the die support I82. The draw ring I84 is supported in theusual manner upon pins connected with the standard rubber or springcushion and this provides the required yielding die element for theoperation under consideration.

The die block I8I is formed with a recess I81 on its upper surface andthe cap center of the ring formed disc M is adapted to fit within therecess and thereby to be definitely located when placed within the diemechanism. The ring formed disc M when so located is in an uprightposition, i. e., in a position reversed from that of the work in theformer die mechanism of Fig. 15.

The corresponding punch mechanism comprises a punch I9I formedintegrally with or carried by a vertically movable crosshead I92. The

punch I-9I is recessedat 1,93 and the surround ing walls of this recessare shaped to snugly fit over the skirt portions I02, |30f the-ringformed disc M. A knockout pad I94 is seated; within the lower end of astepped central opening I95 formed in the punch L91 this opening beingcontiguous with the punch recess I93. Pad I94 is secured to the lowerend of a knockout rod I96 which projects up through and extends abovethe crosshead I92.

A spring I91 surrounds the rod I36 a d rests upon the knockout pad I94:being located, within the upper stepped opening I85 of the punch WI. Theupper end of the spring engages the upper end of the wall of the openingand normally holds the knockout pad I94 in a lowered; positionwherein.its lower face is substantially flush with the lower suriacc of thepunch I91, A projection 1&8 is formed on the knockout pad I84. and isadapted to seat within the drawn center 45 of the ring formed disc Mseated in the die IBL When the unch m hanism des ends Ian-the first legof its stroke the knockout pad I94 with its projecting face 198yieldingly clamps down on the center cap portion'oithe disc M as itrests upon the die I81. This holds the parts against displacement forthe final forming opera-- tion.

In the lower face of the punch I 9I there is a circular forming grooveZN which coaxially and partially surrounds the center area of the punchbeing coextensive with the artially formed U-section III of the disc. Asimilar concentric hemming groove 202- is also formed in the lace of thepunch IM andthis extendsin the region f th d c Nmentainins the ridaeQ-After the disc M has been clamped and the punch parts further descendthe top edges of the flange I15 and the flange I16 of the U- shaped ringsection I'I'I are engaged within the forming groove 29! of the punch andare forced inwardly. At such a time the U -shaped ring part supportedupon a U-shaped seat 203 formed in the upper face of the draw ring I84.

Forcing of the flange edges inwardly results in transforming the Ushapering I" into a completed circular section 204 (Fig. constituting thebody of the pull ring B. At the same time that portion of the flange Iwhich is adjacent the, bridge part C is engaged within the groove 202bent inwardly. The final result is the fo mation of a hem 265 (Fig. 10)interposed betwe 1 the ends of the pull ring B.

The lower tapered Wall of the recess I93 oi the punch till is corrugatedor scalloped as at 236 (Fig. 17) and the spaced tapered wall at the topof the die ISI is also scalloped as at 201. The walls 298, 201 cooperateas the skirt I62 of the disc M is clamped between the walls to transformthe skirt into a scalloped edge 263 (Fig. 10).

This completes the formation of the crown cap A in the die mechanism ofFig. 17. As the punch parts return to their raised position the knockoutpad I94 momentarily remains in place, as the spring IfiI yields, untilthe punch ml is free of the work. Both punch and knockout pad then areraised clear of the crown cap A still resting upon the die member IBI.During this raising of the punch the cushioned mechanism associated withthe draw ring I8 1! causes the latter to lift the drawn cap from the dieIBI whereupon the work is discharged as desired.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent terial-leaving a bridge section intact between acentral portionand an outer surr un n p tion, forming the central portion of saidmaterial within the crescent shaped opening into a cap ement bydrawingan edge into a depending skirt, andhending the marginal edges of theouter portion outside the said opening into a hulki g-circular in crosssection andintegral with and surroundingsaid cap-element for providingan integral cap. removing means for the closure. i

2; The method of preparing" easily removable closnresfor containers andthe like, comprising forming a countersunk panel in sheet material,piercing a crescent shaped opening in said material concentricwith andoutside of said countersunk panel leaving a bridge section intact .be-.tween a central portion and an outer surround- 11 portion, forming thecentral portion of said material within the crescent shaped opening andencircling said countersunk panel into a sealing cap element by drawingan edge into a depending skirt, bending the marginal edges of the outerportion outside the said opening into U=shaped laterally extended walls,and pressing said walls into a pull ring integral with and surroundingsaid cap element for providing an integral cap removing means for theclosure.

3. The method of preparing easily removable closures for containers andthe like, comprising cutting a disc of sheet material, forming acountersunk panel centrally in said disc, piercing a crescent shapedopening in the disc concentric with and outside of said countersunkpanel leaving a. bridge section intact between a central por- I tion andan outer surrounding portion, forming the central portion of said discwithin the crescent shaped opening and encircling said countersunk panelinto a sealing cap element by drawing an edge into a depending skirt,bending the marginal edges or the outer portion outside the said openinginto curved U-shaped laterally extended walls, and pressing said wallsinto a hol low pull ring integral with and surrounding said cap elementfor providing an integral cap removing means for the closure.

4. The method of preparing easily removable closure for containers andthe like, comprising cutting a disc of sheet material whilesimultaneously forming a countersunk panel centrally thereof, piercing acrescent shaped opening in the disc concentric with and outside of saidcountersunk panel leaving a bridge section intact between a centralportion and an outer surrounding portion, forming the central portion ofsaid disc within the crescent shaped opening and encircling saidcountersunk panel into a sealing cap element by drawing an edge into a.depending skirt, trimming the periphery of the disc to a circularoutline, bending the marginal edges of the outer portion outside thesaid opening into curved U-shaped laterally extended walls, and pressingsaid walls into a hollow pull ring circular in cross section andintegral with and sur- 11 rounding said cap element for providing anintegral cap removing means for the closure.

5. The method of preparing easily removable closures for containers andthe like, comprising piercing a crescent shaped opening in a disc ofsheet material leaving a bridge section intact of one side between acentral portion and an outer surrounding portion, drawing the centralportion of said disc within the crescent shaped opening into a. crownseal cap having a depending wall for engagement with a. container,bending the two marginal edges'of the outer portion of the disc outsidethe said opening into laterally extended legs forming U-shaped. wallsbetween the edges of said bridge section, and pressing the edges of thelegs of said walls together into a pull ring integral with andsurrounding the cap for providing an opening means for the closure.

6. The method of preparing easily removable closure for containers andthe like, comprising piercing a crescent shaped opening in sheetmaterial leaving a bridge section intact between a central portion andan outer surrounding portion, forming the central portion of saidmaterial within the crescent shaped opening into a sealing cap elementby drawing an edge into a short skirt merging into said bridge section,bending the marginal edges of the outer portion outside the said'openinginto curved U-shaped laterally extended walls, and simultaneouslyformingsaid short skirt and said bridge section of the closure elementinto a scalloped annulus to define a crown sealing vcap while pressingsaid walls into a hollow pull ring integral with and surroundingthe-said capfor providing an integral cap removing means for theclosure.

crescent shaped opening in the discconce'ntric'""' with and outside ofsaid countersunk panel leaving a bridge section intact between a centralportion and an outer surrounding portion, drawing said central portionoutside of said countersunk panel into a sealing cap element, bendingthe marginal edges of said outer surrounding portion into a curvedinterior upstanding wall extending from one side of said bridge sectionto the other side and a curved exterior upstanding wall surrounding saiddisc, pressing said interior upstanding wall and the corresponding partof said exterior upstanding wall directly adjacent into a hollow pullring integral with and surrounding the closure, and pressing theremaining part of said exterior upstanding wall adjacent said bridgesection into a hemmed edge, the said pull ring providing a cap removingmeans for the closure.

GEORGE C. ERB.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,257,992 Gavaza Mar. 5, 19182,254,682 Hutaff Sept. 2, 1941 FOREIGN PATENTS Number Country Date542,153 Great Britain Dec. 29, 1941

